1. Field of the Invention
The present invention relates to an image pickup apparatus including an image pickup device that receives subject light passed through a photographing optical system and which generates an image signal.
2. Description of the Related Art
Among image pickup apparatuses such as digital cameras and the like, an image pickup apparatus has been proposed in which a fixed type half mirror (semitransparent mirror) is provided on an optical path of subject light passed through a photographing lens, light transmitted by the half mirror is received by an image pickup device, and reflected light is made incident on an AF sensor to enable constant focus detection for a subject.
An image pickup apparatus disclosed in Japanese Patent Laid-Open No. 2004-219439 (hereinafter referred to as Patent Document 1), for example, has an optical low-pass filter (OLPF) made of a rock crystal as a birefringent plate which OLPF is attached to a half mirror as described above, and separates subject light into an ordinary ray and an extraordinary ray by the OLPF, thereby suppressing the occurrence of false color (moire) in a photographed image.